Wireless Power Transmitter OVP Control for Rapid Load Drops
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional wireless power transmitter circuits lack effective over voltage protection (OVP) mechanisms, leading to potential damage when the power level required by the load in the receiver circuit drops rapidly, causing the receiving voltage to exceed the OVP threshold.
Innovation Solution
The wireless power transmitter circuit incorporates a transmission control circuit that monitors the variation rate of the driving current over time and adjusts operation parameters, such as PWM frequency, duty ratio, or input voltage, to reduce the power level of the wireless transmitting power when the variation rate exceeds a threshold, thereby preventing over voltage damage to the receiver circuit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the power level required by the load in the receiver circuit drops rapidly, then the load current decreases quickly, but the receiving voltage sharply increases to exceed the OVP threshold causing circuit damage
Solution Approach 1:
The transmitter circuit predicts future receiving voltage by monitoring the variation rate of driving current and proactively adjusts the power level before the voltage can exceed the OVP threshold. This preliminary action prevents the harmful voltage spike from occurring in the first place, rather than reacting after the problem arises.
Solution Approach 2:
The system continuously monitors the driving current variation rate and uses this feedback to dynamically adjust the power level. When the variation rate exceeds a threshold, the transmitter reduces power output, creating a closed-loop control system that maintains receiving voltage within safe operating limits.
2Power
If the transmitter circuit increases power output to meet load demands, then the receiving voltage remains stable, but the receiver circuit becomes vulnerable to voltage spikes when load changes occur
Solution Approach 1:
The transmitter power level is made dynamic rather than fixed. The system continuously adjusts the power output based on real-time monitoring of driving current variation rate, allowing the power level to adapt to changing load conditions and prevent both under-power and over-voltage scenarios.
Solution Approach 2:
The system changes the power level parameter in response to detected variations in driving current. By monitoring the rate of change and adjusting the power parameter accordingly, the system maintains receiving voltage within safe operating boundaries while meeting load demands.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution effectively prevents damage to the wireless power receiver circuit by reducing the power level of the wireless transmitting power when the receiving voltage approaches the OVP threshold, ensuring reliable operation and protecting the circuit from potential damage.
Implementation Method 1
a resonant transmitter circuit, wherein the resonant transmitter circuit includes a transmission coil and a resonant capacitor which are coupled to each other
Implementation Method 2
a resonant transmitter circuit, wherein the resonant transmitter circuit includes a transmission coil and a resonant capacitor which are coupled to each other
Implementation Method 3
a transmission control circuit, which is configured to operably control the power stage circuit to convert an input power to a driving power according to a pulse width modulation (PWM) control signal
Data Source
AI summary
A wireless power transmitter circuit includes: a power stage circuit including plural switches coupled to a resonant transmitter circuit, wherein the resonant transmitter circuit includes a transmission coil and a resonant capacitor which are coupled to each other; and a transmission control circuit controlling the power stage circuit to convert an input power to a driving power according to a pulse width modulation (PWM) control signal when a corresponding wireless power receiver circuit is near by the resonant transmitter circuit. The driving power drives the resonant transmitter circuit to generate a wireless transmitting power, which is supplied to the corresponding wireless power receiver circuit. When a variation rate of a driving current of the driving power with respect to time exceeds a variation rate threshold, an operation parameter of the power stage circuit is adjusted to reduce a power level of the wireless transmitting power.